Congressional candidates and outside groups in Wisconsin have picked up the pace of TV and radio attack ads as the state's primaries loom three weeks away.

Roll Call counted 10 attack ads released in the past 11 days, including three spots released today.

Most of the ads focus on the race for the state's open Senate seat. Ads from both sides of the aisle have targeted the GOP primary's perceived frontrunners, former Gov. Tommy Thompson and businessman Eric Hovde.

The Club for Growth and former Rep. Mark Neumann, who is also competing in the GOP primary, have been especially critical. Majority PAC, which supports Democrats running for the Senate, and EMILY's List targeted Hovde and Thompson in hopes of aiding presumptive Democratic nominee Rep. Tammy Baldwin.

Neumann released a spot today that infused humor with an allegation that Hovde lacks conservative credentials. The spot compares Hovde to a visual of a dairy cow named "Ol' Bessie" and shows clips of the businessman that purport to show him speaking in favor of corporate bailouts and higher taxes.

"The difference: Ol' Bessie's a real cow. Eric Hovde's not a real conservative," the ad concludes.

http://youtu.be/45F7I3fT9Bc

Other ads rely on more traditional methods of attack. Second district candidate Assemblywoman Kelda Helen Roys released a spot today targeting her Democratic primary opponent Assemblyman Mark Pocan for two of his votes in the state Legislature. The ad features black-and-white images accompanied by dramatic background music and narration. The spot ends with a black-and-white shot of Pocan with the word "Failed" in front of his face.

"What do we really know about politician Mark Pocan? We know he caved in and voted with Scott Walker to throw millions of dollars in tax giveaways to big corporations," the narrator says. "What was he thinking? It's time to say no to Mark Pocan."

http://youtu.be/ai3wJIFXZaA

Thompson complained about the tone of the Senate campaign in an open letter to Hovde and Neumann last week.

"In the last few days I see the attacks flying on television," Thompson wrote in the letter. "Gentlemen, this brand of politics is what is wrong with this country."

But Thompson soon followed the letter with a negative spot of his own. His first negative TV ad attacks Hovde for his time running a hedge fund.

"The Washington game. Eric Hovde's been playing it for 24 years. Hovde ran a hedge fund that used Uncle Sam to buy banks. He traded on government contacts to profit from taxpayer bailouts," the narrator says. "After financial markets collapsed and families lost their life savings, Hovde bragged that he made a forty percent profit. Eric Hovde. He wins. Taxpayers lose."